Goodwill and Other Intangible Assets, Net - Other Intangible Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible total	$ 226.2	$ 256.5
Accumulated amortization	(136.6)	(140.7)
Finite-live intangible asset, net	89.6	115.8
Indefinite-lived intangibles	16.8	22.2
Other Intangible Assets	243.0	278.7
Other intangible assets, net	106.4	138.0
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible total	163.3	176.3
Accumulated amortization	(101.7)	(99.6)
Finite-live intangible asset, net	61.6	76.7
Proprietary technology
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible total	46.7	58.4
Accumulated amortization	(23.4)	(28.1)
Finite-live intangible asset, net	23.3	30.3
Patents and other
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible total	16.2	21.8
Accumulated amortization	(11.5)	(13.0)
Finite-live intangible asset, net	$ 4.7	$ 8.8

Finite And Infinite Lived Intangible Assets Gross

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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

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Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

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